Neutral complex cleaning solution and regeneration method for denitration catalyst with calcium poisoning

Patent metadata

Field	Value
Publication number	US-11439997-B2
Application number	US-201716332967-A
Country	US
Kind code	B2
Filing date	Sep 28, 2017
Priority date	May 24, 2017
Publication date	Sep 13, 2022
Grant date	Sep 13, 2022

Abstract

The invention belongs to the field of nitrogen oxide control in environmental protection science and technology, and particularly relates to the field of regeneration and utilization of SCR denitration catalyst with calcium poisoning, that is a neutral complex cleaning liquid and a regeneration method for denitration catalyst with calcium poisoning. The present invention uses a neutral polyether surfactant as a regeneration and calcium removal reagent to achieve a poisoned catalyst regeneration method with high calcium removal rate, low loss rate of active components and excellent recovery of denitrification activity; wherein the content of the polyether surfactant is in the range of 0.1-1 wt %; by the regeneration method of the present invention, the loading of active components which is required in the conventional regeneration process can be omitted, while the corrosion of equipment and catalyst can be reduced, thus capable of regenerating the denitration catalyst with high efficiency.

First claim

What is claimed is:

1. A regeneration method of denitration catalyst with calcium poisoning, comprising the steps of:
(a) providing a neutral complex cleaning solution comprising active ingredients of polyether surfactant, wherein said polyether surfactant is NP-10 (POLYETHYLENE GLYCOL TRIMETHYLNONYL ETHER);
(b) removing impurities remaining on a surface and inside pores of a poisoned denitration catalyst and drying under room temperature;
(c) after drying, placing the poisoned denitration catalyst in the neutral complex cleaning solution for carrying out an ultrasonic cleaning process for 30 min-2 h and then allow it to stand for 1-24 h; and
(d) after standing, taking out the denitration catalyst and processing washing, air drying, heat drying, and calcination to obtain a regenerated denitration catalyst.

2. The regeneration method of denitration catalyst with calcium poisoning according to claim 1 , in the step (c), the solid to liquid ratio is 1:10-1:100, the cleaning time is 0.5-2 h, the cleaning temperature is 20° C.

3. The regeneration method of denitration catalyst with calcium poisoning according to claim 1 , wherein in step (c), further comprising the substeps of: washing with deionized water, air drying until a water content is below 15-30%, heated drying under 80-160° C. for 12-72 hours, and then increasing temperature to 500-700° C. at a rate of 1-10° C./min and carrying out calcination under air condition for 4-24 hours to obtain the regenerated denitration catalyst is carried out after taking out the denitration catalyst.

4. The regeneration method of denitration catalyst with calcium poisoning according to claim 1 , wherein said neutral complex cleaning solution consists of 0.1-1 wt % of polyether surfactant and deionized water.

5. A regeneration method of denitration catalyst with calcium poisoning, comprising the steps of:
(a) providing a neutral complex cleaning solution comprising active ingredients of NP-10 (POLYETHYLENE GLYCOL TRIMETHYLNONYL ETHER) serving as a polyether surfactant; and
(b) cleaning a poisoned denitration catalyst with calcium poisoning by using the neutral complex cleaning solution,
thereby a denitration efficiency of about 90% and a calcium removal rate of about 88% is achieved while a loss of active ingredients of the poisoned denitration catalyst is minimized.

6. The regeneration method of denitration catalyst with calcium poisoning according to claim 5 , wherein said neutral complex cleaning solution consists of 0.1-1 wt % of polyether surfactant and deionized water.

7. The regeneration method of denitration catalyst with calcium poisoning according to claim 6 , further comprising the steps of:
before step (b), removing impurities remaining on a surface and inside pores of the poisoned denitration catalyst and drying under room temperature until the poisoned catalyst is dried;
in step (b), the cleaning process is an ultrasonic cleaning process which is carried out for 30 min-2 h, and
after step (b), allowing standing time of 1-24 hours.

Assignees

• Univ Tsinghua

Inventors

• Li Junhua
• Li Xiansheng
• Li Xiang
• Peng Yue
• Chen Jianjun

Classifications

• B01J23/92

  of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 · CPC title

• B01J38/52 Primary

  oxygen-containing · CPC title

• B01J23/30

  Tungsten · CPC title

• B01D2255/2045

  Calcium · CPC title

• B01D2255/20776

  Tungsten · CPC title